Single pulse relay



Dec. 2, 1947.

K. SCHLESINGER v SINGLE PULSE, RELAY Filed July so, 1942 Poa/Tn/E 0007-901.

8/6/10!- INPUT JIGIVRL INPUT vvvvvv 21 I \r V 2539 23 61 ii s 69 v (a) \I (a) 7 I INVENTO Kg'i'd auger WW ATTORNEY Patented Dec. 2, 1947 SINGLE PULSE RELAY Kurt Schlesinger, West Lafayette, Ind., assignor to Radio Corporation of America, a corporation of Delaware Application July 30, 1942, Serial No. 452,922

Claims. 1

This invention is related in general to relaying and switching forms of vacuum tube apparatus. In general, the invention set forth is directed to ways and means by which electronic apparatus may be triggered, so to speak, under the control of energizing impulses, and by which provision may be made so that the time period of the triggering or switching operation may be readily controlled.

In the past, it has been known to provide switching or triggering apparatus of the general type known in the art as locking circuits which embodied direct connection by way of resistors or the like between the electrode elements included within two independent thermionic discharge paths which might be embodied in either one or a plurality of vacuum tubes.

Such forms of apparatus essentially provide for a triggering or switching action which took place under the influence of a control signal, and in which the newly assumed state of the apparatus continued until some other form of control signal of opposite polarity arrived to change the state of the operation.

Other forms of apparatus, known in the art as multi-vibrators, which were provided, generally speaking, by the so-called A. C. cross connections between the plate and grid elements of a plurality of independent thermionic discharge paths formed in one or two vacuum tube envelopes provided for a switching between two extreme conditions with the time period of switching and interruption being governed in accordance with a pre-selected time constant of circuit operation, the time constant having been set by the values of the capacity and resistance elements forming the cross connecting circuits. Such forms of multi-vibrators might be of the usual type, or they might even be provided by the so-called cathode coupled type.

The present invention is, in its circuit structural features, somewhat in the nature of a system embodying a direct connection between the output of one thermionic discharge path and the input of a second independent or separate ther1 nionic discharge path and an A. C. or resistancecapacity connection between the output of the second thermionic discharge path and the input of the first thermionic discharge path.

Under these circumstances, a signal impulse arriving upon the system changes its state of thermionic discharge path to the initially controlled thermionic discharge path. At the end of this time period, the system is so constituted that it will return to an initial state and remain that way indefinitely until a new controlling pulse of suitable polarity is applied. Upon the receipt of such a pulse, the system will then perform one cycle of operation. Pulses of opposite polarity which arrive at approximately the end of the natural period synchronize the setting of the relay, but pulses arriving too soon after the start of the operational cycle are completely without eiiect upon the system.

The apparatus, as it will herein be explained, also might be defined as somewhat in the nature of an over-coupled regenerative system in that it is amplitude limited and triggers in either an on or an off position. The feedback path between the second thermionic discharge path and the first thermionic discharge path has a predetermined low frequency limit so that it cannot transmit direct currents but is able to transmit alternating current down to a predetermined low frequency limit. Thus considered, the connection between the output of the second thermionic discharge path and the input of the first thermionic discharge path is essentially in the form of a high-pass filter arrangement which ceases to transmit feedback energy after a period corresponding to its low frequency limit. Then, the relay falls back into a sort of standby condition. The normal plate or anode output energy from the second thermionic discharge path is, in a sense, distorted, while the cathode output from this same thermionic discharge path is distorted in the opposite direction. This invenoperation from one form to another, and the modified operation is maintained for a period which is determined by the time constant of the circuit feeding back energy from the second tion provides for combining the two outputs and, by suitably adjusting the tapping point at which the combined output is derived, a truly square wave output may be obtained with but slight expense of signal output.

Accordingly the invention has, as one of its primary objects, that of providing thermionic apparatus which may be operated under the control of suitable signalling energy, and which, when so controlled, will develop truly square wave energy output and willoperate through one cycle of adjustable time duration for each controlling signal impressed upon the system.

A further object of the invention is that of providing a suitable relay means which is capable of adjustment to provide for an output pulse of any desired time duration which, for instance, may be that corresponding to the time of receipt of a plurality of signal pulses of which those other electrode 33; is, in turn,

than the initial controlling pulse pass by without in any way aiTecting the setting or operation of the relay.

A further object of the invention is to provide a system for triggering controlled apparatus accurately under the control of energizing signal impulsesbymeansof suitable coupling, which results in a differentiation of the inputenergy versus time curve.

Other objects of the invention are to overcome one or more known defects of the prior art forms of switching arrangements, such, for instance, as those used to obtain flat-topped output irom distorted square waves. At the same time there -is provided a relatively simple and'foolproofform of relaying device which can readily be manufactured and placed in operation.

Other objects and advantages will become apparent from a readingof the followingspecification in connection with-the accompanying drawings, of which,

Fig. 1 isa schematic form of circuit arrangem rit showing one form of-the apparatus, and Fig: 2 is constituted by a series of:.-curves for illustrating the preferred form of circuit operation.

Referring now to the drawings, and first-to 'Fig. 1, it will be seen-that the form of relayapparatus herein disclosed'is essentially of the-general type set forth as apart of :my United States patent entitled -Synchronizihg signal generator,

which was granted June 6, .1944 as-No, 2,350,536.

In its preferred form, the invention has been illustrated, as .in the co-pending. application. referred to, as embodied within a single thermionic tube having a plurality of independent discharge paths. -However, it is, of course, apparent, from the outset, that a plurality of separate tubes may be used equally as well. In the disclosed form of the invention, signal energy impulses from a.

source (not shown) are applied to a terminal input point 2 l and fed through a high-pass capacity coupling 23 to the control electrode or grid 25 of the first thermionic discharge path of a vacuum tube 27, which dischargepath is embodied between the cathodei 29and the; anode 3|. This electron flow is controlled by the signal energy applied to the control electrode 25 to vary its potential relative to the cathode.

The other thermionic discharge path is embodied'between the cathode 29", the control electrode or grid 33 and the plate or anode 35. A connection, in the form ofa bleeder or leak resistor 37, is provided between the control electrode -25 and the cathode29, and the cathodes 29 and 29 are connected to ground 39 by Way of the biasing resistor 4}. Under someconditions, the resistor maybe replaced by a battery or other source of potential'servingas a biasing element,

control electrode or grid 33 in the second thermionic discharge path, and this grid or control 7 connected to ground 39 by way of the leak or bleeder resistor 47.

To feed back energy from the secondthermionic discharge path, as it appears at the plate or anode element35 of the tube '2], aconnection is provided by way of the condenser 49 and the bleeder resis- ,and resistor 5! to feed back energy from the second thermionic discharge path as it appears at the :plate or anode 35 to energize the control electrode ,or grid 25.

Suitable. anode potential for the two thermionlc dischargepaths is provided by way of the battery or other potential source 53 connected between ground:39 and the plate or anode elements 3| and the system had a timeconstant shorter than the 35, with the resistors 5'! and connected respectively in the leads to the anode elements 3| and 35.

"-To'derive output energy from thesystem as herein disclosed; connections are made by way of the resistors 59 and 6i, connected respectively jtOlZhC plate or anode 3i and to the cathode 29, and having their common point connected to'an output terminal 6?, and also a second connection ior' deriving output energy is provided by way of the resistors 53 and connecting, in turn, to the anode or plate 35 and the cathode 29"with the common point or junction of the two resistors connected to a second output terminal 69.

The output energy thus derived is conventionally represented by the curves of Fig. 2, where the curve a! representsthe output at the terminal point 6? for a controlledimpulse applied to the control electrode 25 from the terminal 2|, and the curve 6 represents the output at the terminal point 69 under like conditions.

In, considering the operation of the system hereinabove described, it will .be apparent from what has been described that ,thissystem operates in, such a manner as to develop only a,single output pulse at any time, and the duration of the output pulse so derived is determined readily :by an arrangeznent of the time constant of the system which is based upon the value of the capacity 49 and thecombination of the resistors 5'! and 31 serving to function together as bleeder resistorsin the feedback combination. So considered, it will be apparent that the time. constantof the feedback circuit isequal to theproduct ,of the value of the capacity 49 times the sum of .the values of the resistors 5i and 3'! and 55.

Accordingly, in considering the operation ,of this system, it may beassumed that if any .triggeringimpulse is applied to the terminal point f3! that the system. will standby. or operatein such a state that the left portion of th tube 21,

the tub 2'! will be blocked. because .the control electrode. 25 is connectedto the cathode v29' across the resistortl, and consequently, any resultant output, energy will be non-commutative.

The system, however, may ,be triggercdto a different state of operation by an impulse ,of negative polarity applied to the terminal input D,0int ,2l, and thus transferred to the control interval between two successive input pulses ,of

thesame polarity, it would tend to trigger on the .nextpositivepulse applied to the terminalinput point 2! to resume its original state of operation,

but, by virtue of the selection of the time constant provided by the selected values of the capacity 49 and the resistors I and 31, this time can be varied over a substantially reasonably wide range so that the system may be made to trigger after the arrival of a selected plurality of opposite control pulses of predetermined spaced time duration applied at the input terminal 2|.

Considering the s stem further, the cathode and complete outputs of the relay device hereinabove described are represented by the curves a, b and c of Fig. 2, with the plate output from the first half of the tube, that is, at the plate or anode 3|, being represented for instance by the curve a, and the plate output at the second half of the tube, for instance at the plate or anode 35, being represented by curve 0, curve I) representing the cathode output which it will be seen is distorted in the opposite sense from that of the plate outputs, as is the case with the unblocked cathode resistor 4| shown.

Since the output terminals 61 and B9 respectively derive the combined output from the plate and cathode elements of each of the halves of the tube 21, it can be seen that the output of the first half of the tube at the anode and at the cathode may be mixed in the common resistive network formed from the resistors 59 and B l, and similarly,

that the output of the second half of the tube can be mixed in the combined resistive output provided by the resistors 63 and B5.

In any case, it is apparent that in actual practice the resistors 59 and El or 63 and 65 may be in the nature of a potentiometer with the connection of the terminal points 61 and 69 respectively being determined by suitable adjustment of the tapping point, so that the output derived at the terminals 6'! or 69 shall be for terminal 61, the difference between curves a and b as will be represented, for instance, by curve at which is an output pulse of positive polarity, and for terminal 69 will be represented by the difference between the curves 0 and b, which, for instance, is represented by the curve e of Fig. 2 and is of negative polarity for an applied negative pulse at the input or control terminal 2 I.

With a suitable choice of values for the resistors and the capacity and a source of operating voltage 53 chosen as of the order of about 200-volts,

it is apparent that an output voltage of the order of about 50 volts may readily be derived at the terminal points 6'! and 69, it of course being apparent that the square wave output obtainable at the terminal points 6'! and 69 is derived somewhat at the expense of amplitude because of the necessity of obtaining the difference signal from the cathode and the plate outputs, all as indicated by curves at and e of Fig. 2.

It will be noted, from the circuit arrangement shown, that controlling pulses may be applied to the terminal 2| and through the condenser 23 to the control electrode or grid 25. Under these circumstances, the controlling pulse, as it arrives at the terminal 2|, isof negative polarity. However, as also indicated by the drawings, the system may be triggered or operated by a controlling pulse of positive polarity, which signal pulse will be applied to the terminal point 2m and fed through a condenser 23a to the control electrode or grid 33 of the second half of the tube or the second thermionic discharge path.

In this connection, the input coupling to each of the systems is somewhat important, in that it will be apparent that the system hereinabove described is so constituted that it will respond to any decrease in bias upon the control electrode or grid 25, so that the control electrode is carried negative to its previous state, and likewise the system will respond to any increase in bias applied to the control electrode or grid 33 by which this electrode member is carried positive relative to its previous state.

The relay device then starts to perform a single cycle or pulse of operation of predetermined duration. If, for instance, it is intended to transform an input pulse of arbitrary wave form into a square wave of equal duration, the time constant of the relay is adjusted to match the signal period, after which two forms of input coupling are possible, which can be characterized as, first, amplitude coupling, and, second, pulse coupling,

Under thecondition of amplitude coupling, the condensers 23 or 23a are made large, or they may be replaced by a suitable biasing battery or other biasing source so that D. C. coupling is provided. Under such conditions, the relay will respond as soon as the impressed signal wave exceeds a critical value, but its start will not quite coincide with the wave zero point, nor will the backkick, because the two levels are not identical.

For the second condition of pulse coupling, the condensers 23 or 23aare made relatively small or substantially equivalent to a high frequency transformer coupling. Now the pulse to provide the control may be derived from an impressed signal where the rate of change is a maximum, so that it will be observed, as a general rule, the second method of pulse coupling leads to more accurate results and, generally speaking, improved timing.

What I claim is:

1. A relay device comprising electronic apparatus wherein is included a plurality of independent anode and cathode elements between which separate electron discharge paths are developed, and a control electrode means for controlling each of the said thermionic discharge paths, means for supplying control signals to the control electrode included in one of the thermionic discharge paths for controlling the electron flow therein, direct current connection means for energizing the second of said thermionic discharge paths under the control of the signals flowing in the first thermionic discharge path, alternating current connection means comprising a iime'constant circuit including capacity and resistance elements for controlling the energy in the first thermionic discharge path in proportion to the current flowing in the second of said thermionic discharge paths, a pair of resistance elements having one terminal of each connected to the cathode elements included in each thermionic discharge path, a connection from the other terminal of said resistance elements to independent anode elements of each thermionic discharge path, and an output connection to an intermediate point on each of the resistor elements.

2. An electronic relay device comprising thermionic apparatus including means to develop a plurality of independent controllable electronic current paths, means for supplying signals to control the first of the said independent electron current paths, direct current means for controlling the second electron current path in proportion to the current flowing in the first electron current path, regenerative means comprising capacity and resistance elements for controlling the flow oi current in the first electron current path also under the influence of the current flowing in the second electron current path, and resistiveoutput means, Connected to be. energized in accordance with each" electron current flow, said resistive output means each having, one, t er-, mi a1 connected to a common point in each. oi said electron current paths.

3. Electronic apparatus comprising thermionic means having a plurality of electrodesto develop a plurality of independent controllable electronic current paths, means for normally maintaining electron flowv in one of the current paths, resist; area means connecting said electron currentv pathtothe other electron current pathfor normally. interrupting electron flow in the second named. path, means for applying controlling iinpuls'esf'ftofone of the electron currentfpath'sto change. its state of operation to a condition opposite that normally maintained, alternating current. feedback means. comprising capacity nd resistanceelements connecting the second named electron." path with the first electron path to provide -feedback tofthefirst path so that; during per ods offelectron fiow-inthe second path the,

fir path is de-coupled for time periods. at-leastas'fgreat as the time constant providedby theresistance and capacity in the feedback path, resistance'me ans connected-to the output of each electron. path for deriving output energy in accordance with the current flowing. in said path, and. compensating resistance means also connected with said first named resistance means and with the electron path for providing substantially undistorted square wave output from each path.

4, Electronic apparatus comprisingthermionic means having a plurality of electrodes to develop a plurality of independent controllable electronic current paths, means for normally maintaining an, electron fiow in the first of the said electronic currentpaths, resistance means connecting said first electronic current path to the, other electronic current path for normally interrupting electron flow in the second named path,,means for applying controlling impulses of negative polarity to the first of the electronic, current pathsto interrupt the fiow of currenttherein, alternating current feedback means comprising capacity and resistance elements connecting. the second named electronic path with the first electronic path to provide feedback to thefirst path so that, during periods of electron flow inthe second path the first path is de-coupled for time.

periods atleast as great as the time constant providedby the resistance and capacity in the feedback-path, a common resistance element connectedin each electronic path throughwhich-the current flows, output resistance means connected to theputput of each electronic path for deriving ments between each of which anode and cathode,

elements an independently controllable electronic. curent path is developed, means including a con:- trol electrode for normally maintaining the 6166-7 tron flow in the first of the current paths, re-- sistance meansconnecting said electron current path to the other electron current path to normally interrupt current flow in the said other electron path, coupling. means for applying controlling impulsesto the first of the electron current path to change its state of operation. to a condition opposite that normally maintained; a resistor element connecting the control electrode included in the first electron current path to the common cathode elements, an alternating current feedback means comprising serially connected capacity. and resistance elements connecting theanode of the second named electron current path with a control electrode of the first electron currentpath to provide feedback to the first path so that during periods of electron flow in the second-path the first path is decoupled for-time periods at least asgreat as the time constantprovided by the resistance and capacity in the feedback path, and resistive output meanscom nected to. be energized in accordance with each electron current flow, said resistive outputs each having one terminal connected to a common point in each of said electron current paths.

KURT SCHLESINGEB,

REFERENCES CITED The following references are of record in. thefile of this patent:

UNITED STATES PATENTS Number Name Date,

2,265,996 Blumlein Dec. 16, 1941 2,266,526 White Dec; 16, 1941 2,050,059 Koch Aug. 4, 1936 2,262,838 Deloraine et a1 Nov. 18, 1941 OTHER REFERENCES Ultra High Frequency Techniques, by Brainerd- 5 et.al., July 1942, pp. 176-177, D. Van Nostrand 00.,

Inc., New York, N. Y. (Copy in Division 51.) 

